This past weekend in Marin, the posh Northern Californian county just beyond the Golden Gate Bridge, the Mill Valley Film Festival kicked off its 31st season with several premieres and a wide, fascinating range of programs. With a few theatres scattered across Mill Valley and San Rafael’s charming, boutique-laden towns, the festival enjoyed brilliant weather and an air of casual enthusiasm as the event kicked off with high profile guests, a mix of festival circuit favorites and a handful of new…